U.S. patent number 9,232,501 [Application Number 13/940,329] was granted by the patent office on 2016-01-05 for independent resource request method for initial nas signalling.
This patent grant is currently assigned to Tejas Networks Ltd.. The grantee listed for this patent is Tejas Networks Ltd.. Invention is credited to Kumar Rohit.
United States Patent |
9,232,501 |
Rohit |
January 5, 2016 |
Independent resource request method for initial NAS signalling
Abstract
A method for Independent resource request for initial NAS
signaling in a communication network comprising of transporting
service request message of both the UE and RN via Base station to
management entity of Evolved Packet Edge (EPE) within Evolved
Packet Core (EPC), as a signaling message over uplink channel
referred to as "Independent Resource Request" (IR Request) message.
The service request response message from one of the management
entity of EPE or management entities of UE and RN within EPC are
transported as a signaling message to EPE via Base station over the
downlink channel referred to as "Independent Admission Response"
(IA Response). This manages bearer setup signaling as a single
loop, by transportation of "IR Request" signaling message over
uplink and receiving "IA Response" signaling message over downlink
channels.
Inventors: |
Rohit; Kumar (Bihar,
IN) |
Applicant: |
Name |
City |
State |
Country |
Type |
Tejas Networks Ltd. |
Bangalore, Karnataka |
N/A |
IN |
|
|
Assignee: |
Tejas Networks Ltd. (Bangalore,
IN)
|
Family
ID: |
49913932 |
Appl.
No.: |
13/940,329 |
Filed: |
July 12, 2013 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20140016539 A1 |
Jan 16, 2014 |
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Foreign Application Priority Data
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Jul 13, 2012 [IN] |
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2842/CHE/2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W
74/08 (20130101); H04W 72/04 (20130101); H04W
84/047 (20130101) |
Current International
Class: |
H04W
72/04 (20090101); H04W 74/08 (20090101); H04W
84/04 (20090101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO 2010125937 |
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Nov 2010 |
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WO |
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WO 2011035733 |
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Mar 2011 |
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WO |
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WO 2011153716 |
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Dec 2011 |
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WO |
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Primary Examiner: Hamza; Faruk
Assistant Examiner: Decker; Cassandra
Attorney, Agent or Firm: Merchant & Gould P.C.
Claims
I claim:
1. A method for initial NAS signaling in a communication network,
the method comprising: forming an Independent Resource (IR) Request
message for an initial user equipment non-access stratum (UE NAS)
message in an Evolved Packet Edge (EPE) network, wherein the EPE
network comprises at least a user equipment (UE) and one relay node
(RN), and wherein forming the IR request comprises: receiving the
initial UE NAS message, determining that the received initial UE
NAS message is a UE service request message, determining, based on
the determination that the initial UE NAS message is a service
request message, that a requested bearer resource in the UE NAS
message is within available resources of the RN, creating, based on
the determination that the requested bearer resource is not within
the available resources of the RN, a relay node NAS (RN NAS)
message for the initial UE NAS, the RN NAS message comprising a RN
service request message to serve the UE service request, and
forming the IR request message comprising the RN service request
message and the UE service request message; transporting the IR
Request message from the EPE via a Base station to a managing
entity within an evolved packet core (EPC), wherein the managing
entity is one or more network nodes that manage or administer the
UE and the RN, wherein the managing entity is at least one of the
following: a mobility management entity serving the user equipment
(MME_UE), a mobility management entity serving the relay node
(MME_RN), a serving gate way (SGW), a packet gate way (PGW), a
Policy Charging Rules Function (PCRF), and a Home Subscriber Server
(HSS); and receiving Independent Admission (IA) Response via the
Base station for the transported IR Request message from the
managing entity, wherein receiving the IA response comprises:
receiving a first bearer resource allocation for the UE from the
managing entity, and receiving a second bearer resource allocation,
for serving the UE, for the RN from the managing entity.
2. The method of claim 1, wherein transporting the IR request
message comprises simultaneously transporting both the UE NAS
message and the RN NAS message.
3. A method for initial non-access stratum (NAS) signaling in a
communication network, the method comprising: forming an
Independent Resource (IR) Request message for an initial user
equipment NAS (UE NAS) message in an Evolved Packet Edge (EPE)
network, wherein the EPE network comprises a user equipment (UE)
and a relay node (RN), and wherein forming the IR request
comprises: receiving the initial UE NAS message, determining that
the received initial UE NAS message is a UE service request
message, determining, based on the determination that the initial
UE NAS message is a service request message, that a requested
bearer resource in the UE NAS message is within available resources
of the RN, creating, based on the determination that the requested
bearer resource is not within the available resources of the RN, a
relay node NAS (RN NAS) message for the initial UE NAS, the RN NAS
comprising a RN service request message to serve the UE service
request, and forming the IR request message comprising the RN
service request message and the UE service request message;
transporting the IR Request message from the EPE network via a Base
station to a managing entity within an evolved packet core (EPC),
wherein the managing entity comprises one or more network nodes
that manage or administer the UE and the RN; and receiving
Independent Admission (IA) Response from the Base station for the
transported IR Request, from the managing entity within the Evolved
Packed Core (EPC), wherein receiving the IA response comprises:
receiving a first bearer resource allocation for the UE from the
managing entity, and receiving a second bearer resource allocation,
for serving the UE, for the RN from the managing entity.
4. The method of claim 3, wherein transporting the IR request
message comprises simultaneously transporting both the UE NAS
message and the RN NAS message.
5. A network comprising: a user equipment (UE); a base station; a
managing entity; and a relay node (RN); wherein the RN is
configured to: form an independent resource (IR) request message
for an initial user equipment non-access stratum (UE NAS) message
in an Evolved Packet Edge (EPE) network, wherein the EPE network
comprises at least a user equipment (UE) and one relay node (RN),
and wherein the RN being configured to form the IR request message
comprises the RN further being configured to: receive the initial
UE NAS message, determine that the received initial UE NAS message
is a UE service request message, determine, based on the
determination that the initial UE NAS message is a service request
message, that a requested bearer resource in the UE NAS message is
within available resources of the RN, create, based on the
determination that the requested bearer resource is not within the
available resources of the RN, a relay node NAS (RN NAS) message
for the initial UE NAS, the RN NAS comprising a RN service request
message to serve the UE service request, and form the IR request
message comprising the RN service request message and the UE
service request message; transport the IR request message from the
EPE via the base station to the managing entity within an evolved
packet core (EPC), wherein the managing entity is one or more
network nodes that manage or administer the UE and the RN; and
receive independent admission (IA) response via the base station
for the transported IR Request from the managing entity, wherein
the received IA response comprises: a first bearer resource
allocation for the UE from the managing entity, and a second bearer
resource allocation, to serve the UE service request, for the RN
from the managing entity.
6. The network system of claim 5, wherein the managing entity is at
least one of the following: a mobility management entity serving
the user equipment (MME_UE), a mobility management entity serving
the relay node (MME_RN), a serving gate way (SGW), a packet gate
way (PGW), a Policy Charging Rules Function (PCRF), and a Home
Subscriber Server (HSS).
7. The network system of claim 5, wherein the network system is a
wireless communication network and is at least one of the
following: a Code Division Multiple Access (CDMA) networks, a
Universal Terrestrial Radio Access (UTRA) network, a Time Division
Multiple Access (TDMA) network, a Global System for Mobile
Communication (GSM) network, a Frequency Division Multiple Access
(FDMA) network, an Orthogonal Frequency Division Multiple Access
(OFDMA) network, and a Evolved URTA (E-UTRA) network.
8. The network system of claim 5, wherein the RN is transparent to
the UE.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to Indian Patent Application No:
2842/CHE/2012 filed on Jul. 13, 2012, the entire content of which
is hereby expressly incorporated by reference.
FIELD OF THE INVENTION
The present disclosure relates to independent resource request
method for bearer management in a wireless communication network.
In particular, the invention relates to transport of initial NAS
signaling messages on the interface between a relay node and
another node in a mobile communication network.
BACKGROUND
In order to provide better qualities of service and wider
communication ranges between wireless nodes, the concept of relay
station has been introduced in network systems. The purpose of
deploying relay station or Relay Node (RN) in network system is to
extend the serving coverage of base station; hence, user equipment
(UE) which is not within the communication coverage of base station
can access the services provided by relay node as well via base
station.
Wireless network architecture as defined by 3GPP introduces
wireless relay node (RN) entity to extend the coverage of base
station (evolved Node B or eNodeB or eNB). A long term
evolution-advanced (LTE-A) system, as its name implies, is an
evolution of the LTE system, considering relaying for
cost-effective throughput enhancement and coverage extension. For
example, a relay can be deployed at the cell edge where the eNB is
unable to provide required radio quality/throughput for the UEs or
at certain location where radio signals of the eNB cannot
cover.
The Relay Node (RN) forms an independent physical cell. From a user
equipment (UE) perspective, the RN is seen as a usual base station.
The RN is connected via a wireless link to the base station. The
relay node architecture deployment foresees that a RN emulates a
base station for the UE, which means that the UE would see the RN
as a usual base station. From the network side, the RN is seen as a
usual UE by the base station. The base station or eNB, to which the
RN is connected, is called Donor-eNB (DeNB) hereinafter, referred
to as Base station or eNB and operates as a usual base station. The
deployment of RN in the 3GPP network architecture is described in
3GPP Technical Specification 36.306; "Relay architectures for
E-UTRA (LTE-Advanced)".
In order for the user equipment to receive a service from the
network, it needs to establish connectivity via base station, and
initiating Non-Access Stratum (NAS) signaling messages with network
nodes like Mobility Management Entity (MME) serving the UE.
Consequential signaling messages are exchanged between network
nodes to allocate bearer resources for UE and RN to service the UE
request. The above bearer management procedure can be initiated by
UE or the Evolved Packet Core (EPC in terms of 3GPP LTE) or simply
the communication network.
Thus, whenever an initial UE bearer is created, the RN bearer
create or modify procedures may be initiated by the RN. This
increases the latency for the RN to modify/create a new bearer to
service the UE. Thus, some latency is introduced by the RN, when a
bearer or multiple bearers are created for a UE during connection
establishment, leading to delayed access service. Therefore, there
is a need for a bearer management to optimize resources by
effectively setting-up the bearers.
SUMMARY OF THE INVENTION
The summary represents the simplified condensed version of the
claimed subject matter and it is not an extensive disclosure of the
claimed subject matter. The summary neither identifies key or
critical elements nor delineates the scope of the claimed subject
matter. The summary presents the simplified form of the claimed
subject matter and acts as a prelude to the detailed description
that is given below.
The present invention and its embodiments are made to provide for a
feasible solution for facilitating independent resource request
method in a communication network optimizing exchange of initial
NAS signaling communication in managing bearers for UE and RN.
An aspect of the invention provides for a method of managing
initial NAS signaling in a communication network, by transporting
"Independent Resource Request" (IR Request) signaling message from
Evolved Packet Edge (EPE) entities to management entities of EPE
via Base station and receiving "Independent Admission Response" (IA
Response) signaling message for the transported "Independent
Resource Request" from at least one of the said management entity
of EPE by Base station, wherein the said management entity
serves/manages all the entities in the EPE. EPE is a conglomeration
of network nodes comprising of user equipment, relay node and all
other network nodes that communicate over Evolved Packet Core (EPC)
via Base station. Network nodes in the EPE may establish
connectivity external to EPC like Internet or PSTN (Public Switch
Telephone Network).
Another aspect relates to receiving "Independent Admission
Response" (IA Response) signaling message for the transported
"Independent Resource Request" from management entities of EPE by
the Base station, wherein at least one of the said management
entities are not serving/managing the same entities in the EPE.
"Independent Admission Response" message comprises of granted
bearer resources for UE and RN received independently by Base
station from management entity or entities of EPE.
Another aspect relates to network nodes like RN, MME_UE, MME_RN and
systems facilitating the above method of managing bearers each
comprising of at least a receiver, for receiving the said messages,
processors for executing the functions, transmitter for
transmitting messages, a memory for storing information and
retaining instructions for executing functions associated with the
above methods.
Other aspects, advantages, and salient features of the invention
will become apparent to those skilled in the art from the following
detailed description, which, taken in conjunction with the annexed
drawings, discloses exemplary embodiments of the invention.
DESCRIPTION OF THE DRAWINGS
The features, advantages and other aspects of the embodiments of
the present invention will be obvious to any person skilled in the
art to appreciate the invention when read with the following
description taken in conjunction with the accompanying drawings.)
and relay nodes (RNs) as specified in 3GPP LTE (A) network
architectures.
FIG. 1 is an illustration of existing bearer establishment
procedure for user equipments (UE) and relay node (RN) as specified
in 3GPP LTE (A) network architectures.
FIG. 2 shows the network nodes conglomeration between two network
entities in accordance with the principles of the invention.
FIG. 3 is the flow chart of the functions performed by the relay
node in accordance with the embodiments of the invention.
FIG. 4 represents initial UE NAS bearer establishment signaling
loop in accordance with various aspects of the invention.
The figures are not drawn to scale and are illustrated for
simplicity and clarity to help understand the various embodiments
of the present invention. Throughout the drawings it should be
noted that like reference numbers are used to depict the same or
similar elements, features and structures.
DETAILED DESCRIPTION
The following descriptions with reference to the accompanying
drawings are provided to assist in a comprehensive understanding of
exemplary embodiments of the invention as defined by the claims and
their equivalents. Accordingly, those of ordinary skill in the art
will recognize that various changes and modifications of the
embodiments described herein can be made without departing from the
scope and spirit of the invention.
The terms and words used in the following description and claims
are not limited to the bibliographical meanings, but, are merely
used by the inventor to enable a clear and consistent understanding
of the invention. The terms, component, module, system, and the
like are intended to refer to an entity or entities within a
communication network node comprising of; hardware, software, a
combination of hardware and software. For e.g., a component may be,
but not limited to being, a process running on a processor, a
processor, an integrated circuit, or a computer. Both an
application running on a computing device and the computing device
can be a component. A component may be localized on one computer
and/or distributed between two or more computers. The components
may communicate by way of local and/or remote processes.
The present invention and its embodiments are mainly described in
relation to 3GPP specifications and standards (LTE-Advanced) for
applicability of certain exemplary embodiments. The terminology
used is therefore related thereto. Such terminology is used in the
context of describing the embodiments of the invention and it does
not limit the invention in any way. Any other network architecture
or system deployment, etc., may also be utilized as long as it is
compliant with the features described herein.
In particular, embodiments of the present invention may be
applicable in any relay-enhanced (cellular) system with a need for
signaling optimization. Embodiments of the present invention may be
applicable for/in any kind of modern and future communication
network including any mobile/wireless communication
networks/systems.
The following paragraphs will describe various embodiments of the
invention. For exemplary purposes only, most of the embodiments are
outlined according to the LTE-Advanced mobile communication system
with the solution to the problem discussed in the background. The
explanations given below are intended to better understand specific
exemplary embodiments described herein and should not be understood
as limiting the invention to the specific implementations of
processes and functions in a mobile communication network. The
improvements/solutions proposed herein may be readily applied in
architectures/systems having relevance to relay architectures. Some
embodiments of the invention may also make use of standard and
improved procedures of these architectures/systems.
The techniques described herein may be used for various wireless
communication networks such as Code Division Multiple Access (CDMA)
networks, CDMA implementing radio technology such as Universal
Terrestrial Radio Access (UTRA), Time Division Multiple Access
(TDMA) networks, TDMA implementing radio technology such as Global
System for Mobile Communication (GSM), Frequency Division Multiple
Access (FDMA) networks, Orthogonal Frequency Division Multiple
Access (OFDMA) networks, OFDMA implementing radio technology such
as Evolved URTA (E-UTRA), SC-FDMA networks.
User equipment (UE) used in the following description denotes
various terminologies used like an access terminal (AT), wireless
communication device, terminal, wireless handset, computer or
wireless module, wireless module for use with a computer, personal
digital assistant (PDA), tablet computer or device.
In the overall architecture of a network with a relay node (RN), a
relay node has a Base station and a terminal side called as user
equipment (UE). Towards UE the RN behaves as a conventional eNB
using the access link (Uu interface) and the UE is not aware of
whether it is communicating with a relay node or a base station.
Relay nodes are therefore transparent for the UE. Towards base
stations relay nodes initially operate as a UE using the radio
interface to connect to the base station. Once connection is
established and the relay node is configured, the relay uses a
subset of the UE functionality for communication on the backhaul
link (Un interface). In relay architecture eNB acts as a proxy
between the core network and the relay node.
The UEs are connected to the RN by means of a Uu interface and the
RN to the eNB by means of Un interface. When the network e.g.,
Mobility Management Entity (MME) has no valid location or routing
information for the UE, the UE cannot be reached. This is more
likely when the UE is in a state of switched off, or out of
coverage area. 3GPP defines this state as a de-registered state and
this could also happen when the UE is in non-3GPP access. When the
UE is attached to the network e.g., MME, it can receive Core
Network services. This state is defined by 3GPP as registered
state. In this registered state the UE can be in two different
connection management states like RRC_IDLE state and RRC_CONNECTED
state. When no data is being transmitted and the radio resources
are released, the UE has a valid IP configuration. In such idle
state there is no Non-Access Stratum (NAS) signaling connection
between the UE and the network, e.g., MME. Also during the idle
state there is no S1 connection between the eNB and the Serving
Gateway. In the RRC_CONNECTED state, there is an active connection
between the UE and eNB, which implies a communication context being
stored within the eNB for this UE. Both sides can exchange user
data and or signaling messages.
From the wireless network perspective, protocol structure for the
User and Control planes correspond to user data transmission and
signaling transmission. Control plane corresponds to the
information flows actually considered as signaling by Evolved
Universal Terrestrial Radio Access Network (E-UTRAN) and Core
Network. This includes all the RRC (Radio Resource Control) E-UTRAN
signaling (supporting functions such as Radio Bearer management,
radio mobility, user paging) and NAS (Non Access Stratum)
signaling. On the radio interface, the Control plane uses the
Control plane protocol stack namely PDCP (Packet Data Convergence
Protocol), RLC (Radio Link Control), MAC (Medium Access Control)
and PHY (Physical) stack to transport both RRC and Core Network NAS
signaling. The above protocol stack layers support the same
functions for both the User and Control Planes. When a Non-Access
Stratum (NAS) signaling connection needs to be established between
UE and the MME routed via relay node, the UE and the MME shall
enter the connected state. It should be noted that it is possible
that an eNB can have connections to one or more MMEs and
Serving-Gate Way (S-GW) node.
FIG. 1 shows the initial NAS signaling message for bearer
initiation procedure existing in 3GPP LTE specification. UE 20
sends an initial NAS message or service request to the MME_UE 101a,
which is routed through RN 10 and eNB 30. When a NAS layer in the
UE has to send an initial NAS message denoted as `UE NAS Msg` in
FIG. 1, the UE first initiates the establishment of the Radio
Resource Control (RRC) connection over the Uu interface. The RRC
procedures are elaborated in 3GPP specification TS 36.331 available
at www.3gpp.org. In parallel to the establishment of the RRC
connection over the Uu interface, the RN initiates the
establishment of the RRC connection over the Un interface. The RRC
connection establishment procedure over the Uu and Un interfaces
are as per the 3GPP specification.
The NAS message is directed to MME (UE) 101a and the RN 10 is
transparent. The MME_UE 101a understands the message and forwards
it to the SGW/PGW_UE 102a for checking the UE subscription data.
Then the SGW/PGW_UE 102a in conjunction with PCRF (not shown)
authorizes MME_UE 101a to create a dedicated bearer and sends the
message over S11 interface (Interface between S/PGW and MME). On
receiving the response, MME_UE 101a sends bearer setup request to
the UE 20 as an S1-AP message routed through RN 10. RN 10
understands this S1-AP message and initiates RRC configuration
between UE 20 and RN 10. UE 20 sends RRC Reconfiguration Complete
to RN 10. Then RN 10 sends initial context setup response to MME_UE
101a. A bearer setup response may be sent by UE 20 to MME_UE 101a
routed via RN 10 and eNB 30 at NAS level. This process establishes
radio bearers to enable data flow from the SGW/PGW_UE 102a to the
UE 20. After completion of this procedure, the RN 10 may send a NAS
message seeking bearer-resource request to MME_RN 101b via eNB 30.
MME_RN 101b understands the message and provisions bearer resource
allocation to RN 10. Upon receiving bearer resource allocation, RN
10 bearer establishment is completed. Radio resources for the relay
node 10 are allocated so as to serve the already established UE's
bearer requirements. Thus in the above instances, whenever an
initial UE 20 bearer is created, the RN bearer, modify or create
may be initiated subsequently by the RN 10. Thus, some latency is
introduced by the RN, when a bearer or multiple bearers are created
for a UE during connection establishment, leading to delayed access
service.
FIG. 2 shows the network nodes conglomeration between two network
entities in accordance with the principles of the invention.
Network entity 625 is called as Evolved Packet Edge (EPE)
comprising of plurality of network nodes like UE, RN and all other
nodes that communicate with Evolved Packet Core Network entity 675
via Base station 30. Network nodes in the EPE 625 may establish
connectivity external to EPC like Internet 106 or PSTN (Public
Switch Telephone Network) 107. EPC entity 675 comprises of network
nodes like Mobility Management Entity (MME), Serving gate
way/Packet gate way (S/PGW), Policy of Charging Rules Function
(PCRF) etc. These nodes essentially manage the entities in the EPE.
For e.g., a UE bearer resource request is processed and allowed
only by the MME serving the UE. Without any loss of generality, it
is appropriate to indicate MME serving the UEs as MME_UE and MME
serving the RNs as MME_RN. It can happen that MME serving the UEs
and RNs respectively can be one single MME.
As part of bearer management signaling as envisaged, a
communication from EPE 625 comprising of initial bearer resource
request of UE and the consequential bearer resource request of RN
is transported via Base station 30 to EPC 675 as a single signaling
message over uplink channel hereinafter referred to as "Independent
Resource Request" (IR Request) message. The response message
comprising of bearer resource response from either one of the
managing entity or managing entities of EPC 675 are transported as
a single signaling message to Base station 30 over the downlink
channel 652 hereinafter referred to as "Independent Admission
Response" (IA Response). This manages bearer setup signaling loop,
with a single transportation of `IR Request` signaling message and
receiving "IA Response" signaling message over uplink and downlink
channels respectively.
When the UE 20 is in the de-registered state, UE NAS signaling
message that initiates a transition from the de-registered state to
the connected state are `Attach Request`, `Tracking Area Update
Request`, `Service Request` or `Detach Request`. The UE NAS message
received as part of RRC Connection Setup Complete is initial UE NAS
message which is not an encrypted message. If the UE has valid
security parameters stored, then the initial UE NAS message shall
be integrity protected. The request of UE 20 for allocating bearer
resources is referred to as `service request` message.
FIG. 3 is the flow chart representing the functionality 300
performed by the relay node 10, in accordance with the embodiments
of the invention. As described above, the embodied functionality of
RN 10 begins at 301 wherein it receives initial UE NAS Message and
at 302, the initial UE NAS message is checked by the RN to identify
whether it is a `service request` message. If the received message
is a `service request` message then at 303 the RN checks whether
the requested bearer resources of UE are not within the available
resources of the RN to cater to the said UE service request. If the
UE service request is not within its available resources, then at
304, RN creates an RN NAS message, essentially a service request
message for the RN, so as to serve UE service request. At 305, the
relay node forwards UE service request and RN NAS message to Base
station as "Independent Resource Request" messages. At 302, if the
RN finds that the received message is integrity protected or that
the received message is not a `service request` message, or finds
at 303, that the UE service request is within its available
resources so as to cater to the UE bearer requirements then the RN
handles the received initial UE NAS message as other control plane
signaling message at the above stages of 306 and 307 respectively.
"Independent Resource Request" messages received by the Base
station are forwarded to the respective management entities of
EPE.
FIG. 4 represents initial bearer setup signaling loop, with a
single transportation of "Independent Resource Request" signaling
message by EPE entities and receiving "Independent Admission
Response" signaling message by Base station over uplink and
downlink channels respectively, in accordance with the embodiments
of the present invention. Initial UE NAS message that is generated
by UE 20 (Step 1) is received by RN 10 (Step 2). The RN 10 performs
the functions as explained with regard to FIG. 3. After finding
that the message received is an UE service request message, it is
forwarded to the MME_UE 101a via Base station (eNB) 30 (Step 3).
Simultaneously, RN NAS message generated by RN 10 is also forwarded
to the MME_RN 101b via Base station 30 (Step 4). These messages are
transported as "Independent Resource Request" signaling messages to
the respective management entities via Base station. The MME_UE
101a upon receiving the UE service request message processes (Step
5) UE 20 service request and grants utmost initial UE service
request. If MME_UE 101a grants the request, an `S1-AP message for
UE` is generated and forwarded to Base station 30 (Step 6). Base
station 30 receives the `S1-AP message for UE` and forwards to RN
10. If the MME_UE 101a does not grant UE 20 bearer request, then
MME_UE 101a generates `UE NAS message for bearer resource reject`
and forwards it for UE 20 via Base station 30 (Step 11).
The "Independent Resource Request" messages generated by the RN are
essentially a service request message. The RN requests bearer
resource to serve UE bearer Quality of Service (QoS) requirements.
MME_RN 101b processes RN 10 service request. The MME_RN 101b upon
receiving the RN NAS message understands it to be a service request
of the relay node and processes (Step 7) RN 10 service request and
grants utmost RN service request. If MME_RN 101b grants the
request, an `S1-AP message for RN` is generated and forwarded to
Base station 30 (Step 9). If the MME_RN 101b does not grant RN 10
bearer request, then MME_RN 101b generates `RN NAS message for
bearer resource reject` and forwards it for RN 10 via Base station
30 (Step 8). Base station 30 processes the received `S1-AP message
for RN` (Step 10) and performs RRC configuration (Step 12) for the
downstream relay node and forwards `S1-AP messages for the
remaining EPE entities. Performing RRC configuration for the
downstream relay node by Base station and performing RRC
configuration by relay node to the UE 20 (Step 13) are similar to
those functions elaborated in 3GPP specification. For the sake of
clarity, MME_UE processing the UE NAS message and MME_RN processing
the RN NAS message are independent processes and can happen in
parallel.
"Independent Admission Response" (IA Response) that is available to
Base station 30 comprises of bearer resource allocation message
pertaining to the respective EPE entities. For e.g., if MME_UE
grants UE service request x to UE (Y), it generates an `S1-AP
message for UE` and forwards to Base station which may be in the
form of Y(x). Similarly RN NAS messages seeking bearer allocation
for the relay node `P` is forwarded to the respective MME_RN.
MME_RN may grant the same resources `x` to the relay node `P`. In
such cases MME_RN serving the RN `P` may generate an `S1-AP message
for RN` which may be in the form of x(P) and forward it to Base
station. The "Independent Admission Response" from MME_UE i.e.,
Y(x), is understood by the Base station as a message comprising of
allocated bearer resources corresponding to the value of `x` to
UE.
"Independent Admission Response" from MME_RN i.e., x(P) is
understood by the Base station as a message comprising of allocated
bearer resources corresponding to the value of `x` for the relay
node `P`. In the above given example, in case MME_RN grants bearer
resources for the relay node `P` corresponding to the value less
than the granted value of UE i.e., `x-a`, then the `S1-AP message
for RN` would be in the form b(P), (where x-a=b). When this
"Independent Admission Response" message is received by Base
station, it understands as a message comprising of allocated bearer
resources corresponding to the value of `b` for the relay node `P`.
It is also possible that MME_RN managing the relay node `P` denies
granting any of the bearer resources for the relay node `P`, then
the "Independent Admission Response" message that is generated by
MME_RN would be `P( )`. When this "Independent Admission Response"
is received by the Base station, it understands as a message
comprising of `RN NAS message for bearer resource reject`. It
should be noted that in case of a single management entity (like,
MME) serving all the entities in the EPE, the above functions of
independently allocating or denying service requests of UE and RN
are performed by that management entity alone as illustrated
above.
Another embodiment of the invention relates to the implementation
of the above described various embodiments using hardware and
software. It is recognized that the various embodiments of the
invention may be implemented or performed using computing devices
(processors). A computing device or processor may for e.g., be
general purpose processors, digital signal processors (DSP),
application specific integrated circuits (ASIC), field programmable
gate arrays (FPGA) or other programmable logic devices, etc. The
various embodiments of the invention may also be performed or
embodied by a combination of these devices.
Further, the various embodiments of the invention may also be
implemented by means of software modules, which are executed by a
processor or directly in hardware. Also a combination of software
modules and a hardware implementation may be possible. The software
modules may be stored on any kind of computer readable storage
media, for example RAM, EPROM, EEPROM, flash memory, registers,
hard disks, CD-ROM, DVD, etc.
It is to be noted that respective functional blocks or elements
according to above-described aspects can be implemented by any
known means, either in hardware and/or software, respectively, if
it is only adapted to perform the described functions of the
respective parts. The mentioned method, steps can be realized in
individual functional blocks or by individual devices, or one or
more of the method, steps can be realized in a single functional
block or by a single device.
The present invention also covers any conceivable combination of
method steps and operations described above, and any conceivable
combination of nodes, apparatuses, modules or elements described
above, as long as the above-described concepts of methodology and
structural arrangement are applicable.
It would be appreciated by a person skilled in the art that
numerous variations and/or modifications may be made to the present
invention as shown in the specific embodiments without departing
from the spirit or scope of the invention as broadly described. The
present embodiments are, therefore, to be considered in all
respects to be illustrative and not restrictive.
* * * * *
References